simplify your HTML building.

#haitch

alternative pronunciation for the letter "H"

The haitch library provides a builder for composing HTML elements together. The element nodes are functional and will only be rendered when invoked.

Why write your HTML in templates when you can do it in Python?

#Features

• Compose HTML elements.
• Lazily evaluate DOM tree.
• 100% test coverage.
• 100% type annotated codebase.
• Zero dependencies.
• Document common elements.

#Roadmap

• Document all HTML elements from MDN Web Docs.
• Support common third-party plugins like htmx and alpine.

#Requirements

Python 3.8+

#Quickstart

Install haitch using pip:

$ pip install haitch

Import the library like so:

import haitch as H

By importing the root module, you now have access to any element you want:

# Render known `h1` tag.
h1 = H.h1("Hello, world")
print(h1) # <h1>Hello, world</h1>

# Render custom `foo` tag (useful for web components).
foo = H.foo("Hello, world")
print(foo) # <foo>Hello, world!</foo>

Here is a simple example that showcases the advantage of writing HTML in Python. Let's say we want an ordered list of stored org domain emails:

# Fetch emails from data store.
emails = ["jane@aol.com", "bob@example.com", "mark@mail.org", "karen@hr.org"]

# Build an ordered list with org domain emails.
dom = H.ol(class_="email-list")(
    H.li(H.a(href=f"mailto:{email}")(email))
    for email in sorted(emails)
    if email.endswith(".org")
)

print(dom)
# <ol class="email-list">
#   <li><a href="mailto:karen@hr.org">karen@hr.org</a></li>
#   <li><a href="mailto:mark@mail.org">mark@mail.org</a></li>
# </ol>

The printed output above is prettified for better readability. The actual output is a minified string with no formatting.

#Documentation

Activate your virtual environment where haitch is installed and run:

$ python -c "help('haitch')"

#Motivation

Inspired by the fantastic htbuilder library as an alternative to template engines. The library met most of my needs, but I really wanted to expand its functionality by leveraging modern Python features like typing. This coincided with my excitement for Hypermedia-Driven Applications (HDAs) with tools like htmx and alpine.

While writing HDAs has simplified my application logic, the lack of autocompletion and diagnostics in templates are quite annoying. Therefore, my goal with this package is to make writing HTML as simple and fun as writing normal Python code by writing normal Python code.

#Non-goals

The following features will not be supported:

• Deprecated elements and attributes: if you want to use them, that is fine by me as haitch supports generic elements and attributes. However, I am not going to write the annotations and documentation for them.
• 100% input validation: this library is meant to assist the developer to write valid HTML with the help of type annotations and documentation. In the end, it is up to the developer and browser to verify that the input is of the correct type. So for example, I will not add any validation to make sure that a <col> element is directly nested inside of a <colgroup> element or that the span attribute for the <col> element is a positive integer.

#Releases

This library adheres to semantic versioning and keeps a changelog.

#Examples

Intended to help you to integrate haitch into your application:

• FastAPI minimal example
• Django minimal example

#License

haitch is distributed under the terms of the BSD-3-Clause license.